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Cannot send / receive Fax - PAP2-NA

I have an analog fax machine that I have set up as a fax extension in 3cx. Incoming calls to the fax DID are routed to the fax and it answers but no faxes are ever sent or received. My provider is Broadvox and they moved our line to a new platform to better support faxing. Between 3cx, PAP2, and Braodvox somewhere there is a problem. Any ideas where to start? I assume to start with the pap2, but i could spend forever there if thats not the problem. Phone calls via the pap2 work fine.

PAP-2T is not supporting fax or at least is not understanding T.38.
Most probably Broadvox is using T.38 as fax protocol and 3CX is not able to negotiate the older T.30 (i.e. G.711a/µ) for the session.
You can easily debug it with wireshark or check and ask Broadvox to disable T.38.

3cx told me to have my provider turn ON t.38 for fax to email (3cx fax)

so do I need it ON or OFF? I understand 3cx doesnt support outbound fax at all, does that mean it just absolutely wont work or should i be able to continue with messing with things and eventually get fax service?

I really dont care about outbound fax, but I would like inbound faxing to work.

This means either you forward your incoming T.38 faxes to 3CX system fax extension (fax to email) or using T.30 (forced by provider) to VoIP gateway (PAP-2T or other device, SPA-2102/3102 are also T.38 compliant).

I have a T.38 provider with SPA-2102/3102 working fine using T.38 with other IP PBX. I don't see a reason why incoming / outgoing T.38 fax will not pass through to/from T.38 capable device connected in 3CX (i.e. SPA-2102/3102).

In your case, if the PAP-2T worked before with your provider, means T.38 fax was not used. If you don't care / need outgoing faxes -- try using the system fax extension (to email) and ask the provider for T.38 switched on (more reliable).